• Title/Summary/Keyword: Impeller

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A numerical study on the acoustic characteristics of splitter type centrifugal impeller (스플리터형 원심형 임펠러의 소음 특성에 대한 연구)

  • Jeon, Wan-Ho;Chung, Phil-Joong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.113-118
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    • 2000
  • Centrifugal pump are widely used and the noise generated by these machines causes one of the most serious problems. In general, the centrifugal pump noise is often dominated by tones at BPF(blade passage frequency) and its higher harmonics. This is a consequence of the strong interaction between the flow discharged from the impeller and the cutoff in the casing. However, only a few researches have been carried out on predicting the noise because of the difficulty in obtaining detailed information about the flow field and casing effects on noise radiation. The objective of this study is to develop a prediction method for the unsteady flow field and the acoustic pressure field of a centrifugal pump, and to calculate the effects of small vanes that are attached in original impeller-splitter impeller. We assume that the impeller rotates with a constant angular velocity and the flow field around the impeller is incompressible and inviscid. So, a discrete vortex method(DVM) is used to model the centrifugal pump and to calculate the flow field. The force of each element on the blade is calculated by the unsteady Bernoulli equation. Lowson's method is used to predict the acoustic source. The splitter impeller changes the acoustic characteristics as well as performance. Two-splitter type impeller is good for acoustic characteristics.

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Analysis of the Axial Thrust Force of a Centrifugal Impeller with a Thrust Labyrinth Seal at its Backside (스러스트 래버린스 실을 배면에 갖는 원심형 임펠러의 축력 해석)

  • Park, Jun Hyuk;Kim, Tae Ho
    • Tribology and Lubricants
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    • v.37 no.1
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    • pp.31-40
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    • 2021
  • This study describes the effects of a thrust labyrinth seal applied to the backside of a centrifugal impeller on the axial thrust force for high speed turbomachinery. The bulk flow model using Neumann's equation calculates the seal cavity pressures and leakage flow rate of the thrust labyrinth seal based on three configurations: teeth-on-rotor (TOR), teeth-on-stator (TOS), and interlocking labyrinth seal (ILS). Prediction results show that the ILS is superior to the TOR and TOS in terms of leakage flow rate. A mathematical model of a centrifugal impeller with a thrust labyrinth seal on its backside calculates the force components corresponding to the impeller inlet, shroud, impeller backside outer, backside seal, and backside inner pressures. A summation of the force components renders the total axial thrust force acting on the centrifugal impeller. The Newton-Raphson numerical scheme iteratively calculates the pressures and leakage flow rate through the impeller wall gap. The prediction results reveal that the leakage flow rate and total axial thrust force increase with rotor speed, and the ILS significantly decreases the leakage flow rate, whereas it slightly increases the axial thrust force when compared to TOR and TOS. Increasing the seal clearance causes an increase in the leakage flow rate and a slight decrease in the axial thrust force with the ILS.

Multi-objective robust optimization method for the modified epoxy resin sheet molding compounds of the impeller

  • Qu, Xiaozhang;Liu, Guiping;Duan, Shuyong;Yang, Jichu
    • Journal of Computational Design and Engineering
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    • v.3 no.3
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    • pp.179-190
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    • 2016
  • A kind of modified epoxy resin sheet molding compounds of the impeller has been designed. Through the test, the non-metal impeller has a better environmental aging performance, but must do the waterproof processing design. In order to improve the stability of the impeller vibration design, the influence of uncertainty factors is considered, and a multi-objective robust optimization method is proposed to reduce the weight of the impeller. Firstly, based on the fluid-structure interaction, the analysis model of the impeller vibration is constructed. Secondly, the optimal approximate model of the impeller is constructed by using the Latin hypercube and radial basis function, and the fitting and optimization accuracy of the approximate model is improved by increasing the sample points. Finally, the micro multi-objective genetic algorithm is applied to the robust optimization of approximate model, and the Monte Carlo simulation and Sobol sampling techniques are used for reliability analysis. By comparing the results of the deterministic, different sigma levels and different materials, the multi-objective optimization of the SMC molding impeller can meet the requirements of engineering stability and lightweight. And the effectiveness of the proposed multi-objective robust optimization method is verified by the error analysis. After the SMC molding and the robust optimization of the impeller, the optimized rate reached 42.5%, which greatly improved the economic benefit, and greatly reduce the vibration of the ventilation system.

Optimal Design of Impeller according to Blade Shape Variation Using CFD Simulation (CFD를 이용한 블레이드 형상 변화에 따른 블로워 임펠러 최적설계)

  • Yu, Da-Mi;Kim, Semo;Jang, Hye-Lim;Han, Dae-Hyun;Kang, Lae-Hyong
    • Journal of Aerospace System Engineering
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    • v.13 no.1
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    • pp.29-37
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    • 2019
  • The objective of this study was to investigate the influence of the blade shape on the impeller performance, for design optimizing of the high airflow impeller. First, the quantity, angle, and length of blades, which are considered to have a large influence on the impeller performance, were selected as design variables. Then, 27 cases of impeller shapes were selected according to the design of experiment (DOE). To predict the conduct of the blower based on the selected impeller shape, flow analysis was performed using the immersed solid method of ANSYS CFX. In the CFD results, the highest airflow was expected in the impeller having a combination of 50 EA, $6^{\circ}$ and 5 mm. Finally, a blower with the original impeller shape and the optimized impeller shape was fabricated using a 3D printer, and the analysis tendency and experimental tendency were verified through experiments.

Numerical Prediction of a Performance Change in a Compressor Shrouded Impeller with Cavity Leakage Flow (슈라우드 임펠러에서 누설 유동이 압축기 성능에 미치는 영향에 대한 수치해석적 연구)

  • Choi, Min-Uk;Joo, Won-Gu;Park, Jun-Young;Yoon, Eui-Soo;Choi, Sang-Kyu
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.3
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    • pp.64-69
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    • 2012
  • Generally the Shrouded type impeller is considered to free from the loss of tip leakage flow, but it is actually not possible to complete sealing between the rotating impeller and the sealing which is stay still. As a result, there is the possibility of flow leaking between impeller exit to entrance, especially with high pressure ratio compressor machine. The Cavity leakage flow is expected to influence negative effect on a machine performance and also inner flow structure. In this study, Impeller with shroud-casing gap leakage flow is simulated by numerical method (Using CFX 12.1). The influence of leakage flow on compressor performance and efficiency will be analysed, also detail flowfield change will posted.

Design Optimization of a Centrifugal Pump Impeller using RSM and Design of Volute (반응표면기법을 이용한 원심펌프 임펠러 최적설계 및 벌류트 설계)

  • Pyun, Kwon-Bum;Kim, Joon-Hyung;Choi, Young-Seok;Yoon, Joon-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.3
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    • pp.39-45
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    • 2012
  • In this study, optimization of the impeller and design of volute were carried out in order to improve the performance of a centrifugal pump. Design parameters from vane plane development for impeller design were selected, and effect of the design parameters on the performance of the pump was analyzed by using Response Surface Methodology(RSM) to optimized impeller. In addition, total pump design method was suggested by designing volute which was suitable for the optimized impeller through volute design where Stepanoff theory was applied and numerical analysis.

Hydrodynamic forces of impeller shroud and wear-ring seal on centrifugal pump (고성능 원심펌프에서 임펠러 시라우드 및 마모 시일의 유체가진력 해석)

  • Ha, Tae-Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.1
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    • pp.102-110
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    • 1998
  • The analysis of lateral hydrodynamic forces in the leakage path between a shrouded pump impeller through wear-ring seal and its housing is presented. Governing equations are derived based on Bulk-flow and Hirs' turbulent lubrication model. By using a perturbation analysis and a numerical integration method, governing equations are solved to yield leakage and rotordynamic coefficients of force developed by the impeller shroud and wear-ring seal. The variation of rotordynamic coefficients of pump impeller shroud and wear-ring seal is analyzed as parameters of rotor speed, pressure difference, shroud clearance, wear-ring seal clearance, and circumferential velocity at the entrance of impeller shroud for a typical multi-stage centrifugal pump.

Computational Study on the Performance of the Impeller in Centrifugal Pump (원심펌프 임펠러의 성능에 대한 전산해석적 연구)

  • Kim, Won-Kap;Kang, Shin-Hyoung
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.1 s.6
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    • pp.10-18
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    • 2000
  • This paper reports the impeller performance of centrifugal pump, modified HES65-250. Developed CFD code uses SIMPLE algorithm, power-law scheme, standard $k-{\espilon}$ turbulence model in curvilinear coordinate system. The calculations are conducted for 5 cases, from 0.6 to 1.4 of flow rate ratio with 0.2 increment. The flow characteristics inside of impeller are analysed. The results show that reversal flows exist at the inlet of impeller which have small rotary stagnation pressure. The obtained results are compared with the experimental data at impeller exit and shows good qualitative agreement.

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Performance Analysis on Centrifugal Pump Using Impeller/Volute Interaction (임펠러/벌류트의 상호작용을 이용한 원심펌프의 성능예측)

  • Lee Gee-Soo;Choi Chang-Ho;Kim Jin-Han;Yang Soo-Seok
    • 한국전산유체공학회:학술대회논문집
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    • 2001.05a
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    • pp.203-208
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    • 2001
  • Any circumferential variations of the impeller exit flow conditions influences on the volute inlet flow conditions. All these interactions are strongly coupled phd affect consequently the performance of centrifugal pumps. In this paper, a commercial CFD code, which solves three-dimensional quasi-steady Wavier-Stokes equations with an impeller/volute interaction, is used for the prediction of a centrifugal pump performance. The simplified model of an impeller/volute interaction requires affordable computing time and provides relevant results. As a result, detailed flow structures such as pressure rise, recovery and loss mechanism on the centrifugal pumps are obtained. Especially, hydraulic performances are compared between the case of impeller only and the case of impeller with volute configuration. In addition, pump performance at off-design operation are observed and discussed.

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Development of CAM Automation Module(E-ICAM) for 5-axis Machining of Impeller (A Study on Configuration of Module) (임펠러의 5축 CAM 자동화 모듈(E-ICAM)의 개발 (모듈 구성에 관한 연구))

  • Jung, Hyoun-Chul;Hwang, Jong-Dae;Jung, Yoon-Gyo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.4
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    • pp.109-114
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    • 2011
  • An impeller is difficult to machine because of severe collision due to the complex shape, overlapping and twisted shape that form impeller blades. So, most CAM software companies have developed CAM module for manufacturing impeller in addition to their CAM software. But it is not still easy for inexperienced users to machine impellers. The purpose of this paper is the development of automatic CAM module for manufacturing impeller(E-ICAM) which is based on visual basic language and it is used CATIA graphical environment in order to be easily machining impellers. Automatic CAM module for manufacturing of impellers generates tool path, and proposes recommended cutting condition according to the material of stock and tool. In addition, it has also included a post processor for 5-axis control machining. Therefore the user can easily machine impellers using this automation module.